1. Field
This application relates generally to wireless communication and more specifically, but not exclusively, to a keep-alive indication that may be used to maintain data transmission.
2. Background
A communication device may establish and maintain communication with another communication device in a variety of ways. For example, for broadcast communication a transmitting device may unilaterally transmit a stream of data whereby any number of receiving devices may be free to listen to the data stream at any time. In contrast, for multicast communication two or more devices may cooperate to establish communication where participation in the communication is limited to those particular devices.
In these and other forms of communication systems, once communication commences between devices, a given device may or may not keep track of whether another device is still actively participating in the communication. For example, in some communication systems a device that is not actively transmitting may be configured to periodically transmit keep-alive messages to other devices. In this way, any device that receives the keep-alive messages will be informed that the other device is still participating in the communication (e.g., receiving data). As a result, the device that receives the keep-alive messages may continue communicating with (e.g., transmitting data to) the other device. Conversely, if keep-alive messages are not received from a given device for a certain period of time, communication with that device may be terminated. Thus, such systems may make efficient use of the available system bandwidth since a transmission may only occur when another device is listening to the transmission.
In contrast, in a communication system such as a broadcast system the broadcasting device may transmit regardless of whether any receiving devices are currently receiving the transmission. That is, the broadcasting device may simply continue its transmission until the completion of the event being broadcast. Thus, in this case a receiving device need not coordinate with the transmitting device to receive the broadcast. Rather, the receiving device may elect to listen or not listen to the broadcast at will. A potential advantage of this type of system is that little or no overhead may be needed to establish communication between devices. However, such a system may not utilize bandwidth efficiently since the broadcasting device may continue to transmit even when there are no receivers listening to the transmission.